Here's a scary/stupid trick to pull if you, like me, are a finalist for Biggest Email Pack Rat On The Internet.
Open Apple Mail's Preferences, select the "General" tab, and change Dock unread count from Inbox Only to All Mailboxes. I double-dare you.
Or, it might just be too depressing. I went from a mere(!) 355 unread messages to…
Let's see, at an average of just under 2 minutes each (clocked over a recent week), cleaning that out would take me some 78 days, 2 hours and 24 minutes, during which some 31,000 new emails (not including auto-filtered spam at ~85% of total incoming email) would arrive. Assuming I could stay awake that long. Caffeine is The Elixir of Life™, but… "filling a baby's eyedropper from a raging waterfall" does not even begin to do the image justice. Maybe the old Ragú ad slogan, "It's In There".
There has to be a better way.